From a892ff39b22ca2ae8810b52ba987102e7dd0dd2a Mon Sep 17 00:00:00 2001
From: CaitSith2 <d_good@caitsith2.com>
Date: Wed, 5 Aug 2020 08:48:25 -0700
Subject: [PATCH] Backport terrorpin ai fix from enemizer. (and fix a bug with
 it.)

---
 LTTP_RND_GeneralBugfixes.asm |  1 +
 hooks.asm                    |  9 +++++++++
 tables.asm                   |  4 ++++
 terrorpin.asm                | 19 +++++++++++++++++++
 4 files changed, 33 insertions(+)
 create mode 100644 terrorpin.asm

diff --git a/LTTP_RND_GeneralBugfixes.asm b/LTTP_RND_GeneralBugfixes.asm
index c52b101..a43c171 100644
--- a/LTTP_RND_GeneralBugfixes.asm
+++ b/LTTP_RND_GeneralBugfixes.asm
@@ -213,6 +213,7 @@ incsrc elder.asm
 incsrc toast.asm
 incsrc darkroomitems.asm
 incsrc multiworld.asm
+incsrc terrorpin.asm
 warnpc $A58000
 
 ;org $228000 ; contrib area
diff --git a/hooks.asm b/hooks.asm
index 6227b18..586ce64 100755
--- a/hooks.asm
+++ b/hooks.asm
@@ -2560,3 +2560,12 @@ CheckIfReading:
     CPX #$04
     RTS
 ;================================================================================
+
+;================================================================================
+; Terrorpin AI fix
+;--------------------------------------------------------------------------------
+org $1EB2B1 ; sprite_terrorpin.asm(57) : AND.b #$03 : STA $0DE0, X ; 5 bytes
+JSL FixTerrorpin ; 4 bytes
+NOP				 ; 1 byte
+;--------------------------------------------------------------------------------
+
diff --git a/tables.asm b/tables.asm
index 4707bea..0ef8c1c 100644
--- a/tables.asm
+++ b/tables.asm
@@ -1824,6 +1824,10 @@ org $30E36D ; PC 0x18636D
 ;BerserkerMulti.world Seed GUID
 db #$00, #$00, #$00, #$00, #$00, #$00, #$00, #$00, #$00, #$00, #$00, #$00, #$00, #$00, #$00, #$00
 
+org $30E37D ; PC 0x18637D
+Enable_TerrorPin_AI_Fix:
+db #$01
+
 ;--------------------------------------------------------------------------------
 ; 0x186380 - 187FFF (unused)
 ;--------------------------------------------------------------------------------
diff --git a/terrorpin.asm b/terrorpin.asm
new file mode 100644
index 0000000..9be8def
--- /dev/null
+++ b/terrorpin.asm
@@ -0,0 +1,19 @@
+;================================================================================
+; Terrorpin AI Fixes
+;================================================================================
+FixTerrorpin:
+{
+    PHA ;save A so that checking the option doesn't smoke A
+    LDA.b Enable_TerrorPin_AI_Fix : BNE .new ; check if option is on
+        PLA ;restore A
+        ; do the old code that smokes A
+        AND.b #$03 : STA $0DE0, X
+    RTL
+
+    .new
+        PLA ; Restore A
+        PHA ; save A so the orignal code doesn't kill it
+        AND.b #$03 : STA $0DE0, X ; restore what we overwrote
+        PLA ; restore A so the AND/BNE in the original code actually does something
+	RTL
+}